add $select support to data source.

Author: gmurray81

DataSource.DataProviders.OData/ODataSampleApp/MainWindow.xaml.cs

@@ -34,8 +34,17 @@ public MainWindow()
             };
 
             source.SortDescriptions.Add(new DataSourceSortDescription("OrderID", true));
-            source.FilterExpressions.Add(DataSourceFilterExpression.CreateSimpleOperation(
-                "ShipName", DataSourceExpressionOperatorType.Equal, "Wartian Herkku"));
+            //source.FilterExpressions.Add(DataSourceFilterExpression.CreateSimpleOperation(
+            //    "ShipName", DataSourceExpressionOperatorType.Equal, "Wartian Herkku"));
+
+            //Task.Delay(8000).ContinueWith((t) =>
+            //{
+            //    Dispatcher.BeginInvoke(new Action(() =>
+            //    {
+            //        grid1.SortDescriptions.Clear();
+            //        grid1.SortDescriptions.Add(new DataSourceSortDescription("OrderID", false));
+            //    }));
+            //});
 
             grid1.ItemsSource = source;
         }

ODataDataProvider/ODataVirtualDataSourceDataProvider.cs

@@ -103,7 +103,8 @@ private ODataVirtualDataSourceDataProviderWorkerSettings GetWorkerSettings()
                 PageLoaded = _callback,
                 ExecutionContext = _executionContext,
                 SortDescriptions = _sortDescriptions,
-                FilterExpressions = _filterExpressions
+                FilterExpressions = _filterExpressions,
+                DesiredProperties = _desiredProperties
             };
         }
 
@@ -337,6 +338,20 @@ public DataSourceSortDescriptionCollection SortDescriptions
             }
         }
 
+        private string[] _desiredProperties;
+        public string[] DesiredProperties
+        {
+            get
+            {
+                return _desiredProperties;
+            }
+            set
+            {
+                _desiredProperties = value;
+                QueueAutoRefresh();
+            }
+        }
+
         private DataSourceFilterExpressionCollection _filterExpressions;
         public DataSourceFilterExpressionCollection FilterExpressions
         {

ODataDataProvider/ODataVirtualDataSourceDataProviderWorker.cs

@@ -24,6 +24,8 @@ internal class ODataVirtualDataSourceDataProviderWorkerSettings
         public DataSourceSortDescriptionCollection SortDescriptions { get; set; }
 
         public DataSourceFilterExpressionCollection FilterExpressions { get; set; }
+
+        public string[] DesiredProperties { get; set; }
     }
 
 
@@ -45,6 +47,7 @@ internal class ODataVirtualDataSourceDataProviderWorker
         private string _entitySet;
         private DataSourceSortDescriptionCollection _sortDescriptions;
         private DataSourceFilterExpressionCollection _filterExpressions;
+        private string[] _desiredPropeties;
 
         protected DataSourceSortDescriptionCollection SortDescriptions
         {
@@ -62,6 +65,14 @@ protected DataSourceFilterExpressionCollection FilterExpressions
             }
         }
 
+        protected string[] DesiredProperties
+        {
+            get
+            {
+                return _desiredPropeties;
+            }
+        }
+
         private List<ODataFeedAnnotations> _annotations =
             new List<ODataFeedAnnotations>();
 
@@ -112,6 +123,7 @@ public ODataVirtualDataSourceDataProviderWorker(ODataVirtualDataSourceDataProvid
             _entitySet = settings.EntitySet;
             _sortDescriptions = settings.SortDescriptions;
             _filterExpressions = settings.FilterExpressions;
+            _desiredPropeties = settings.DesiredProperties;
             Task.Factory.StartNew(() => DoWork(), TaskCreationOptions.LongRunning);
         }        
 
@@ -228,6 +240,7 @@ private IDataSourceSchema ResolveSchema(IDictionary<string, object> item)
         }
 
         private string _filterString = null;
+        private string _selectedString = null;
 
         protected override void MakeTaskForRequest(AsyncDataSourcePageRequest request, int retryDelay)
         {
@@ -295,6 +308,11 @@ protected override void MakeTaskForRequest(AsyncDataSourcePageRequest request, i
                         }
                     }
                 }
+
+                if (DesiredProperties != null && DesiredProperties.Length > 0)
+                {
+                    client = client.Select(DesiredProperties);   
+                }
             }
 
             Task<IEnumerable<IDictionary<string, object>>> task = client